A turbocharger compresses air prior to directing the air into an engine. Supplying the engine with compressed air (“charge air”) may allow for more complete combustion of fuel within the engine. This may result in improved power density and better engine efficiency. However, compressing the air may also increase a temperature of the air. Supplying the engine with heated air may lead to an undesirable increase in the amount of emissions discharged from the engine. Also, because engines generally produce large quantities of heat already, adding heated air to the engine may increase the operating temperature of the engine, thus reducing efficiency and possibly resulting in excessive wear of engine components.
An inter-stage charge air cooler or intercooler is often disposed between a first compressor and a second compressor of a two-stage turbocharger arrangement and used to reduce engine emissions by cooling the air from the first stage compressor before it enters the second stage compressor. The intercooler lowers combustion temperatures and increases density of the air, thus improving engine thermodynamic efficiency, increasing engine power output, and extending engine component life. Also, disposing the intercooler between the first stage compressor and second stage compressor may increase the efficiency of the second stage compressor and the component life.
In addition to the intercooler, a primary charge air cooler or aftercooler is often located downstream of the second stage compressor, and used to further cool the air before it enters the engine. Like the intercooler, the aftercooler lowers combustion temperatures and increases the density of the air, thus further increasing engine efficiency, increasing engine power output, and improving engine component life.
An exemplary engine utilizing both an intercooler and an aftercooler is disclosed in U.S. Patent Publication No. 2010/0192890 of Brooks et al. that published on Aug. 5, 2010 (the '890 publication). Specifically, the '890 publication describes an engine with two-stage turbocharging, having an intercooler located between compressor stages and a completely separate aftercooler located downstream of a second compressor stage.
Although the engine of the '890 publication may include both an intercooler and an aftercooler, it may still be less than optimal. In particular, because the intercooler and the aftercooler of the '890 publication are separate assemblies, a significant amount of space and ducting may be required to connect these assemblies to the other components. This extra ducting may increase costs and decrease performance of the engine.
The cooling assembly of the present disclosure solves one or more of the problems set forth above and/or other problems of the prior art.